This invention relates to a paper feeding device for a printer and more particularly to a forced paper feeding device which is provided at the push side of a platen, is synchronized with the platen, and feeds papers employing sprocket holes and a tractor sprocket wheel.
A forced paper feeding device providing a tractor sprocket wheel which is located at the push side of a platen and is synchronized with the platen rotation is well-known. But in such a type of paper feeding device, although the papers are force fed, papers loaded over the platen are fed by friction between the platen and the paper (i.e., no force feed). Additionally, it is general practice that paper feeding by the platen is set shorter than the forced paper feeding by the tractor since the friction coefficient between the paper and the platen varies and the diameter of the platen changes due to its environmental condition. Thereby, the papers loaded over the platen are sometimes loosened. Because of such loosened papers, feeding by the platen is reduced and line spacing is shortended accordingly. If such a condition continues, the printing quality is lowered and additionally the printing causes noise due to the printing on the loosened paper.